I've started having an issue starting a few weeks ago where my PC will randomly stop outputting video entirely. At first to fix it I found the following steps worked:
press power button to shut off PC > reboot in safe mode with networking so it uses windows video drivers > go to device manager, uninstall Radeon RX Vega under display drivers > restart normally > reinstall drivers
Recently when this happens it works sometimes with just a restart. It seems to have nothing to do with the load my driver is under as it happens when I'm playing games and when I'm just browsing chrome. I've tried the recommended and latest versions of the drivers, reinstalling using Adrenalin, and neither work. Sometimes it won't crash for a week and then randomly crash several times a day.
I haven't changed my PC's hardware since I built it two years ago. Yes, the first thing I checked was the HDMI cable.
Specs: OS: Windows 10 CPU: i5-9600k RAM: G.SKILL Ripjaws V Series 16GB Mobo: Gigabyte B360 WiFi PSU: Corsair CX650